The number of people planning to move home has doubled since the beginning of the year as confidence in the property market remains strong, research shows today.

About 15 per cent of people now claim they plan to buy a new house before next winter, compared with just seven per cent at the beginning of the year, according to Alliance & Leicester.

The group said that while not everybody would act on these plans, the increase in intentions showed people felt confident about both house prices and borrowing.

The number of people looking to buy their first home has also increased by nearly a third since January, with 16 per cent of under 30s - the key first-time buyer age group - now planning to move, up from 12 per cent at the beginning of the year.

Alliance & Leicester said that, despite high house prices, affordability still remained good and was far better than during 1990 when many people defaulted on their mortgages.

It said people taking out a mortgage during the first three months of the year spent an average of 14 per cent of their household income on interest payments, the lowest level since the second quarter of 2004, and well down on 1990's level of 27 per cent. Among all mortgage holders, people had an average outstanding mortgage debt of £85,992 at the end of April, nearly ten per cent more than last year.

But despite this, affordability remained unchanged with interest accounting for ten per cent of their income due to lower interest rates and rising pay, increasing to 21 per cent if capital repayments were taken into account.

"Increased first-time buyer activity enables others to move up the ladder. Affordability remains good, which means that despite renewed mortgage borrowing, consumers are taking a responsible attitude. April's slightly cooler market should also give some reassurance that the market is not returning to an unsustainable boom."

Meanwhile existing homeowners are making attempts to boost their property value with half planning to carry out home improvements during the coming 12 months, spending an average of nearly £5,500 each.

According to research by Capital One Homeowner Loans, about 47 per cent of people have a project planned for the coming year, with an estimated 1.8 million people expecting to spend more than £10,000 on the work.

The main reason people gave for carrying out improvements was to boost its value, with 32 per cent citing this as their main motivator for carrying out the work. Owners expected improvements to add around £10,000 to the asking price of their home.

However, 15 per cent claimed they were doing the work because the high cost of moving, 14 per cent of people said they needed more space for their growing family and 12 per cent of people did not want to take on a bigger mortgage.

Other reasons for carrying out improvements included not being able to find a suitable property to move to, pressure from partners and children and keeping up with friends and neighbours.